The application is based upon and claims the benefit of Japanese Patent Applications No. 2000-118093 filed on Apr. 19, 2000, No. 2000-136934 filed on May 10, 2000, No. 2000-172091 filed on Jun. 8, 2000, No. 2000-195887 filed on Jun. 29, 2000, No. 2000-200021 filed on Jun. 30, 2000, and No. 2000-353257 filed on Nov. 20, 2000, the contents of which are incorporated herein by reference.
1. Field of the Invention
This invention relates to a coolant cooled type semiconductor device.
2. Description of the Related Arts
To improve cooling characteristics of semiconductor modules that contain semiconductor chips having terminals, it has been proposed that water cooling type cooling members are made in contact with semiconductor modules so as to cool these semiconductor modules. Also, Japanese Laid-open Patent Application No. Hei-6-291223 has proposed a double-sided heat-radiating type semiconductor module in which heat is radiated from both surfaces of this semiconductor module.
However, in the above-described conventional water-cooling type semiconductor modules, a cooling member must be joined to the semiconductor modules, while maintaining superior heat transfer characteristics. To realize such superior heat transfer characteristics, there is the best way such that an electrode (also having heat transfer function) that is exposed from the main surfaces of the semiconductor modules is joined to the cooling member by a soldering material.
If the cooling member is a cooling unit through which water or coolant passes, the cooling unit may be connected to either a refrigerating cycle apparatus or a cooling water circulating apparatus. Therefore, the above-explained electrode member of the semiconductor module and the cooling member is set to a predetermined potential (normally, ground potential) equal to that of the refrigerating cycle apparatus, or the cooling water circulating apparatus.
However, when such an electrically insulating spacer is employed, since the electrode member of the semiconductor module cannot be joined to the cooling member, the electrode member of the semiconductor module and also the cooling member must be strongly pressed against the electrically insulating spacer under such a condition that uniform pinching pressure is given to the respective face portions in order to reduce the thermal resistance between the electrode member of the semiconductor module and the cooling member.
The above-described construction in which both the semiconductor module and the cooling member are strongly pressed against the insulating spacer under uniform pinching pressure would induce the complex entire structure. Also, the pinching force cannot be controlled easily. In other words, when the pinching force is low, the thermal resistance between the semiconductor module and the cooling member is increased, so that the cooling capability is lowered. To the contrary, when the pinching force is excessively high, the semiconductor chips built in the semiconductor module are broken.
Also, in order to cool double-sided of a large number of these semiconductor chips, or double-sided cooling type semiconductor card modules, a large number of the above-explained cooling members are branched, resulting in complex structures and increased manufacture cost. These increase the risk that fluids may be leaked due to an increased total number of joint places of the coolant distribution tubes.
The present invention has been made to solve the above-explained problem, and therefore, has an object to provide a coolant cooled type semiconductor device having a simple structure and also capable of realizing a superior heat radiation capability, and further capable of reducing a possibility of fluid leakages.
According to a first aspect of the present invention, a semiconductor device is disposed between a first cooling member and a second cooling member, a first insulating member is disposed between the first cooling member and the semiconductor device a second insulating member is disposed between the second cooling member and the semiconductor device. In this way, the semiconductor is insulated from the first and the second cooling member while heat generated in the semiconductor device radiates through the cooling members.
According to a second aspect of the present invention, a cooled type semiconductor device comprises: first and second cooling members, through which a coolant flows, pinching a semiconductor device therebetween tightly by a fixing member.
It is preferable that a cooling unit has a flat shape and has a first portion corresponding to the first cooling member, a second portion corresponding to the second cooling member, and a folded portion connecting the first and second portions.
According to a third aspect of the present invention, a cooled type semiconductor device comprises: a first semiconductor chip having a high side semiconductor switching element which has a first positive and a first negative electrodes, a second semiconductor chip having a low side semiconductor switching element which has a second positive and a second negative electrodes, wherein the first negative electrode and the second positive electrode are connected to a common mid terminal, the first positive electrode is connected to a high potential terminal and the second negative electrode is connected to a low potential terminal whose electric potential is lower than that of the high potential terminal.
According to a fourth aspect of the present invention, a cooled type semiconductor module comprising: a first heat radiating plate disposed on a main surface of the module and a second heat radiating plate disposed on a back surface of the module, wherein a heat sink contacts the first radiating plate, and a biasing-holding member connected with the heat sink presses the semiconductor module to the heat sink.